title: Rapid versus delayed stimulation of feeding by the endogenously released AgRP neuron mediators GABA, NPY, and AgRP.
abstract: Agouti-related peptide (AgRP) neurons of the hypothalamus release a fast transmitter (GABA) in addition to neuropeptides (neuropeptide Y [NPY] and Agouti-related peptide [AgRP]). This raises questions as to their respective functions. The acute activation of AgRP neurons robustly promotes food intake, while central injections of AgRP, NPY, or GABA agonist results in the marked escalation of food consumption with temporal variance. Given the orexigenic capability of all three of these neuroactive substances in conjunction with their coexpression in AgRP neurons, we looked to unravel their relative temporal role in driving food intake. After the acute stimulation of AgRP neurons with DREADD technology, we found that either GABA or NPY is required for the rapid stimulation of feeding, and the neuropeptide AgRP, through action on MC4 receptors, is sufficient to induce feeding over a delayed yet prolonged period. These studies help to elucidate the neurochemical mechanisms of AgRP neurons in controlling temporally distinct phases of eating.
authors.affiliation: Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Krashes
authors.forename: Bhavik P
authors.initials: BP
authors.lastname: Shah
authors.forename: Shuichi
authors.initials: S
authors.lastname: Koda
authors.forename: Bradford B
authors.initials: BB
authors.lastname: Lowell
mesh_terms: D054369:Agouti-Related Protein / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D003024:Clozapine / Q000031:analogs & derivatives / Q000494:pharmacology; D004435:Eating / Q000187:drug effects; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009478:Neuropeptide Y / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D044105:Receptor, Melanocortin, Type 4 / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D050495:Vesicular Inhibitory Amino Acid Transport Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D054369:Agouti-Related Protein; D009478:Neuropeptide Y; D044105:Receptor, Melanocortin, Type 4; D050495:Vesicular Inhibitory Amino Acid Transport Proteins; C492244:Viaat protein, mouse; D005680:gamma-Aminobutyric Acid; D003024:Clozapine; C079149:clozapine N-oxide